The Husqvarna 55 Chainsaw is a professional-grade chainsaw featuring a 50.1cc engine, automatic oiler, inertia-activated chain brake, and anti-vibration system. This parts manual provides detailed diagrams, part numbers, and ordering information for all components, including the engine assembly, cutting equipment, fuel system, ignition, clutch, and housing. Below are key sections for identification, engine parts, cutting attachments, fuel system, ignition system, and ordering.
Identify your Husqvarna 55 model using the serial number plate located on the rear housing. Key specifications for parts compatibility.
| Feature | Specification |
|---|---|
| Engine Displacement | 50.1 cc (3.06 cu. in.) |
| Power Output | 3.0 hp |
| Fuel Tank Capacity | 0.55 L (18.6 fl. oz.) |
| Oil Tank Capacity | 0.26 L (8.8 fl. oz.) |
| Recommended Bar Length | 13" to 20" (33 cm to 50 cm) |
| Chain Pitch | 3/8" or .325" |
| Chain Gauge | 0.050" or 0.058" |
| Dry Weight (w/o bar & chain) | 5.3 kg (11.7 lbs) |
| Ignition System | Electronic, SEM |
| Spark Plug | NGK BPMR7A (Champion RCJ7Y) |
Crankcase, crankshaft, bearings, seals, and associated hardware.
WARNING! Engine disassembly requires specialized tools. Incorrect assembly can cause severe damage or injury.
Components for the top-end engine rebuild.
CAUTION! Always match piston and cylinder as a set for optimal performance. Clean carbon deposits before installation.
Components for spark generation and engine timing.
Ignition Module (SEM) (Part # 501 84 89-01): Includes coil and timing advance.
Spark Plug Cap (Part # 501 84 90-01): Resistor-type cap.
Stop Switch (Part # 501 84 91-01): Grounds ignition to stop engine.
Wiring Harness (Part # 501 84 92-01): Connects ignition, switch, and starter.
Ignition: Fixed timing at 25° BTDC. Air Gap: 0.3 mm (0.012") between flywheel and coil legs.
Centrifugal clutch, sprocket, and drive components.
Tip: Inspect clutch drum and sprocket for wear. Replace if grooves exceed 0.5 mm depth.
Supports guide bars, chains, and sprockets.
WARNING! Always use matched chain and bar specifications. Worn sprockets accelerate chain wear.
Rear handle, front handle, and anti-vibration mounts.
Rear Handle (Part # 501 85 01-01): Includes throttle trigger and safety lockout.
Front Handle (Part # 501 85 02-01): Top handle with vibration dampeners.
Anti-Vibration Mounts (Part # 501 85 03-01): Set of four rubber isolators.
Starter Assembly (Part # 501 85 04-01): Recoil starter with pulley and rope.
Starter Rope (Part # 501 85 05-01): 110 cm length, 3.5 mm diameter.
Rubber mounts between engine and handles reduce operator fatigue.
Inertia-activated chain brake, right-hand guard, chain catcher, and throttle lockout.
CAUTION! Inspect chain brake function before each use. Replace if handle movement exceeds 2 mm free play.
| Symptom | Common Replacement Part | Part Number |
|---|---|---|
| Engine won't start, no spark | Ignition Module | 501 84 89-01 |
| Loss of power, excessive smoke | Piston & Cylinder Kit | 501 87 42-01 / 501 84 78-01 |
| Chain won't oil | Oil Pump Assembly | 501 85 06-01 |
| Hard starting, fuel issues | Carburetor Repair Kit | 501 85 07-01 |
| Excessive vibration | Anti-Vibration Mount Set | 501 85 03-01 |
Genuine Parts: Use only Husqvarna-approved parts for safety and warranty.
Support: 1-800-487-5962; www.husqvarna.com/us/support